Method for forming thickened disposable aluminum foil lunch box
Technical Field
The invention relates to the field of lunch box preparation, in particular to a method for forming a thickened disposable aluminum foil lunch box.
Background
An aluminum foil lunch box is a widely used tableware. The thickness of the aluminum foil lunch box is generally between 0.03mm and 0.20mm, and the aluminum foil lunch box can be divided into two types of crumpled and uncreped. Can also be divided into disposable and repeated use. The tinfoil lunch box is a common domestic tinfoil lunch box, which is actually a 3-series or 8-series aluminum ingot raw material, is cold-rolled or hot-rolled into an aluminum foil master roll with uniform thickness, smooth surface, no pinholes, no dust particles and no peculiar smell, and is subjected to a production process of one-time full-automatic cold stamping forming by special equipment and dies.
Aluminium foil tin paper cutlery box is going to the slice that is in curling toward stamping forming, is carrying out cold stamping forming's in-process, often can have following problem:
1) because aluminium foil cutlery box is convenient for transport and deposit before the punching press, often be the reel form, in-process carrying out the punching press need expand it, the influence aluminium foil tinfoil that receives self toughness often has the crooked fold of certain radian after expanding, cause the incomplete deformation of cutlery box among the punching press process, the punching press in-process is difficult to carry out the secondary compaction and cut off to the edge in cutlery box punching press region, guarantee the marginal smoothness after the cutlery box punching press, also be difficult to in time accomplish the punching press the cutlery box of back joint in stamping equipment and push away, promote the operating efficiency of cutlery box stamping forming operation.
2) Traditional aluminium foil cutlery box punching press is accomplished the back, its surplus aluminium foil often is thin strip form, and because often there is many folds deformation on the pressure surplus aluminium foil in the stamping process, driven conveying equipment is difficult to carry the in-process of collecting to the surplus aluminium foil, be difficult to carry out the quadratic to the fold part on the aluminium foil and smooth the compaction, single rolling length when promotion rolling equipment carries out the rolling operation, and reduce the aluminium foil rolling in-process and produce cracked probability, further promote the operating efficiency of aluminium foil cutlery box preparation operation.
Disclosure of Invention
In order to solve the above problems, the present invention provides a method for forming a thickened disposable aluminum foil lunch box, which can solve the problems mentioned in the background art.
In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose: the utility model provides a disposable aluminium foil cutlery box forming method of thickened type, it has used a disposable aluminium foil cutlery box forming device of thickened type, this disposable aluminium foil cutlery box forming device of thickened type includes mounting bracket, supporting legs, support frame, carries the pivot, smooths the pivot, rolling pivot, punching press mechanism and winding mechanism, adopts the disposable aluminium foil cutlery box forming device of above-mentioned thickened type to the disposable aluminium foil cutlery box shaping operation of thickened type concrete method as follows:
s1, preparing raw materials: firstly, manually sleeving an aluminum foil coil to be used for manufacturing a lunch box on a conveying rotating shaft, pulling out one end of the aluminum foil, sequentially penetrating through a punching mechanism and a winding mechanism, and sleeving the aluminum foil coil on the winding rotating shaft;
s2, conveying and smoothing: the winding rotating shaft is driven to rotate through the winding mechanism, the aluminum foil is further driven to be conveyed and wound, and the aluminum foil before being stamped is flattened and compacted through the flattening rotating shaft;
s3, stamping forming: performing punch forming operation on the flattened aluminum foil through a punching mechanism while performing the step S2 to obtain a finished product of the aluminum foil and tin foil heat-preservation lunch box;
s4, collecting the blanking: after the step S3 is completed, collecting and storing the punched aluminum foil lunch boxes through manual work or the existing mechanical hand, performing secondary smoothing and compaction on the punched residual aluminum foils through a winding mechanism, and then winding the residual waste materials through a winding rotating shaft;
the utility model discloses a lunch box, including mounting bracket, support frame, rolling pivot, the corner evenly is provided with the supporting legs all around to the mounting bracket lower extreme, the transport pivot is installed through the bearing in the front side upper end of mounting bracket, the support frame is evenly installed to bilateral symmetry on the mounting bracket, evenly install through the bearing between the support frame and smooth the pivot, the rolling pivot is installed through the bearing in the rear side upper end of mounting bracket, punching press mechanism is installed to the middle part upper end of mounting bracket, be located and install winding mechanism and rolling pivot between the mounting bracket, the setting smooth the two-way aluminium foil that leans on of pivot accessible and smooth the compaction to effect before to the punching operation, avoid.
The punching mechanism comprises a lifting sliding frame, a lifting sliding rod, a first punching seat, a second punching seat, a punching spring, a connecting rope, guide wheels, a lifting cylinder, a punching sliding block, a punching notch, a limiting block, a limiting sliding chute, a limiting spring, a cutting knife and sponge, wherein the lifting sliding frame is uniformly and symmetrically arranged in the middle of the mounting frame left and right, the lifting sliding rod is uniformly arranged in the lifting sliding frame, the first punching seat is arranged at the upper end of the lifting sliding rod in a sliding fit manner, the first punching seat is connected with the lifting sliding frame through the punching spring, the second punching seat is arranged at the lower end of the lifting sliding rod in a sliding fit manner, the guide wheels are uniformly arranged on the mounting frame below the two ends of the first punching seat in a rotating fit manner, the connecting rope is uniformly arranged on the side wall of the first punching seat, the other end of the connecting rope is connected with the second punching seat, and the middle, the mounting frame below the punching seat II is provided with a lifting cylinder, an output shaft of the lifting cylinder is connected with the punching seat II, the side walls of the punching seat I and the punching seat II are symmetrically provided with sponges with the same structural shape, the punching seat II positioned at the inner side of the sponge is symmetrically provided with punching slide blocks in a sliding fit mode, the punching seat II is internally provided with a punching cylinder, the output shaft of the punching cylinder is connected with the punching slide blocks, the side walls of the punching slide blocks are uniformly provided with limit blocks, the punching seat I is symmetrically provided with punching notches matched with the punching slide blocks, the punching notches are uniformly provided with limit slide grooves, the limit blocks in the limit slide grooves are uniformly provided with limit blocks with the same structural shape as the punching seat II in a sliding fit mode, the limit blocks in the limit slide grooves are connected with the punching seat I through limit springs, and the punching seat II is uniformly provided with cutting, the sponge that sets up can carry out elasticity to the outward flange of cutlery box when the punching press and lean on tightly, carries out the secondary of aluminium foil and smooths compaction operation, can realize cutting the operation to the circumference of aluminium foil through cutting the sword and the joint cooperation between the notch of stepping down, promotes the planarization at cutlery box edge, can realize the preliminary design of cutlery box through mutually cooperating between punching press slider and the punching press notch.
Further, the winding mechanism comprises a positioning frame, a limiting slip ring, a driving rotating shaft, a compaction gear, a driving chain, a winding motor, a synchronous wheel, a synchronous belt, a compaction bottom plate, a compaction chute, a compaction spring, a compaction rotating shaft and a compaction unit, wherein the positioning frame is symmetrically and uniformly arranged on the left side and the right side of the mounting frame between the winding rotating shaft and the lifting sliding frame, the limiting slip ring is symmetrically and uniformly arranged on the side wall of the positioning frame close to the middle part of the mounting frame from top to bottom, the driving rotating shaft is symmetrically and uniformly arranged on the positioning frame on the inner side of the positioning slip ring from top to bottom through a bearing, the driving gear is uniformly arranged at one end of the driving rotating shaft through a spline and is connected with the driving gear through the driving chain, the compaction gear is uniformly arranged at the other end of the driving gear from top to bottom, and connect the transmission through the hold-in range between the synchronizing wheel, install the rolling motor through the motor cabinet on the locating rack, the output shaft of rolling motor is connected with the drive pivot through the shaft coupling, be located the mounting bracket between locating rack and the rolling pivot on bilateral symmetry install the compaction bottom plate, the compaction spout has been seted up to the upper and lower symmetry on the compaction bottom plate, install the compaction pivot through sliding fit's mode symmetry in the compaction spout, and be connected through the compaction spring between compaction pivot and the compaction bottom plate, install the compaction unit on the spacing sliding ring, the compaction pivot of setting can lean on pressing from both sides tightly the aluminium foil after pacifying under the promotion of compaction spring, the thickness change that avoids the rolling pivot constantly to increase when carrying out the rolling operation causes the slope fold of aluminium foil, reduce remaining aluminium foil and take place cracked probability at rolling in.
Furthermore, the compaction unit comprises a compaction rotating ring, compaction elastic sheets, a compaction sliding frame, a positioning spring and a positioning rotating shaft, the compaction rotating ring is uniformly sleeved on the driving rotating shaft through a spline, the compaction elastic sheets are uniformly arranged on the side wall of the compaction rotating ring along the circumferential direction of the side wall, the compaction sliding frame is uniformly arranged on the limiting sliding ring through sliding fit, the compaction sliding frame is connected with the limiting sliding ring through the positioning spring, the positioning rotating shaft is uniformly arranged on the compaction sliding frame through rotating fit, the fold deformation area on the aluminum foil strip can be smoothed and compacted through the elastic abutting action of the compacting elastic sheets symmetrically arranged at the upper side and the lower side of the aluminum foil, the compacting sliding frames symmetrically arranged at the upper side and the lower side can enable the positioning rotating shaft to always abut against the aluminum foil under the pushing action of the positioning spring, the two-way rigid supporting action of the positioning rotating shaft can be used for carrying out secondary compaction operation on the flattened aluminum foil, so that the flatness of residual materials of the aluminum foil after punch forming is improved.
Furthermore, the cutting knife is positioned on the inner side of the sponge, and a yielding notch of the yielding cutting knife is formed in the first stamping seat.
Furthermore, the compaction shell fragment be arcuation fan-shaped structure, the compaction shell fragment can be followed the compaction swivel and rotated the while self produce recoverable bending deformation.
Furthermore, the compaction rotating shaft can adapt to the thickness change of the aluminum foil when the rolling rotating shaft rolls the aluminum foil under the elastic connection of the compaction spring, and the aluminum foil is prevented from being broken due to the fact that an overlarge inclination angle is formed between the aluminum foil and the driving rotating shaft in the rolling process.
The invention has the beneficial effects that:
1. the smoothing rotating shaft can smooth and compact the aluminum foil before the stamping operation through the bidirectional abutting effect, so that incomplete deformation of the lunch box in the stamping process caused by deformation of partial wrinkles on the aluminum foil is avoided;
2. the sponge arranged in the punching mechanism of the invention can elastically abut and clamp the outer edge of the lunch box during punching, and carry out secondary smoothing and compacting operation of the aluminum foil, the circumferential cutting operation of the aluminum foil can be realized through the clamping fit between the cutting knife and the abdication notch, the smoothness of the edge of the lunch box is improved, the preliminary shaping of the lunch box can be realized through the mutual matching between the stamping sliding block and the stamping notch, the bottom of the lunch box can generate bending deformation arranged at intervals through the clamping matching between the limiting block and the limiting sliding groove, the structural toughness in the later use process of the lunch box and the bearing capacity when food is filled are improved, the limiting spring is arranged to push the limiting block positioned on the inner side of the limiting sliding groove to reset and move through self elasticity, the lunch box positioned on the inner side of the stamping notch is further pushed to drop through the abutting action, and the operation efficiency of the lunch box preparation operation is improved;
3. according to the rolling mechanism, the fold deformation area on the aluminum foil strip can be flattened and compacted through the elastic abutting action of the compacting elastic sheets symmetrically arranged on the upper side and the lower side of the aluminum foil, the compacting sliding frames symmetrically arranged up and down can enable the positioning rotating shaft to always abut against the aluminum foil under the pushing action of the positioning spring, the secondary compacting operation can be performed on the flattened aluminum foil through the bidirectional rigid abutting action of the positioning rotating shaft, the smoothness of residual materials of the aluminum foil after stamping forming and the rolling length of the aluminum foil in the single rolling operation process are improved, the arranged compacting rotating shaft can abut against and clamp the flattened aluminum foil under the pushing action of the compacting spring, the inclined folds of the aluminum foil caused by the continuously increased thickness change of the rolling rotating shaft during the rolling operation are avoided, and the probability of breakage of the residual aluminum foil in the rolling process is reduced.
Drawings
The invention is further illustrated with reference to the following figures and examples.
FIG. 1 is a flow chart of the present invention;
FIG. 2 is a front view of the overall structure of the present invention;
FIG. 3 is a first cross-sectional view of the present invention;
FIG. 4 is a second cross-sectional view of the present invention;
FIG. 5 is a schematic view of a partial perspective structure of the stamping mechanism of the present invention;
FIG. 6 is a partial perspective view of the winding mechanism of the present invention;
fig. 7 is a schematic partial perspective view of a first stamping seat and a second stamping seat according to the present invention.
Detailed Description
In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments, it being understood that the specific embodiments described herein are only for the purpose of explaining the present invention and are not intended to limit the present invention.
Referring to fig. 1-7, a method for forming a thickened disposable aluminum foil lunch box uses a thickened disposable aluminum foil lunch box forming device, which comprises a mounting frame 1, supporting legs 2, a supporting frame 3, a conveying rotating shaft 4, a smoothing rotating shaft 5, a winding rotating shaft 6, a stamping mechanism 7 and a winding mechanism 8, and the method comprises the following specific steps when the thickened disposable aluminum foil lunch box forming device is used for forming the thickened disposable aluminum foil lunch box:
s1, preparing raw materials: firstly, manually sleeving an aluminum foil coil to be used for manufacturing a lunch box on a conveying rotating shaft 4, pulling out one end of the aluminum foil, sequentially penetrating through a punching mechanism 7 and a winding mechanism 8, and sleeving the aluminum foil coil on a winding rotating shaft 6;
s2, conveying and smoothing: the winding rotating shaft 6 is driven to rotate through the winding mechanism 8, the aluminum foil is further driven to be conveyed and wound, and the aluminum foil before being punched is flattened and compacted through the flattening rotating shaft 5;
s3, stamping forming: in the step S2, performing punch forming operation on the flattened aluminum foil through the punching mechanism 7 to obtain a finished product of the aluminum foil-tin paper heat-preservation lunch box;
s4, collecting the blanking: after the step S3 is completed, the punched aluminum foil lunch boxes are collected and stored by a manual or existing manipulator, the punched residual aluminum foils are flattened and compacted for the second time by the winding mechanism 8, and then the residual waste materials are wound by the winding rotating shaft 6;
supporting legs 2 are evenly arranged at the corners around the lower end of the mounting frame 1, a conveying rotating shaft 4 is installed at the upper end of the front side of the mounting frame 1 through a bearing, supporting frames 3 are evenly installed on the mounting frame 1 in a bilateral symmetry mode, a smoothing rotating shaft 5 is evenly installed between the supporting frames 3 through a bearing, a winding rotating shaft 6 is installed at the upper end of the rear side of the mounting frame 1 through a bearing, a stamping mechanism 7 is installed at the upper end of the middle of the mounting frame 1, and a winding mechanism 8 is installed on the mounting frame 1 between the stamping mechanism 7 and the.
The punching mechanism 7 comprises a lifting sliding frame 7a, a lifting slide bar 7b, a first punching seat 7c, a second punching seat 7d, a punching spring 7e, a connecting rope 7f, a guide wheel 7g, a lifting cylinder 7h, a punching cylinder 7j, a punching slide block 7k, a punching notch 7m, a limiting block 7n, a limiting sliding chute 7p, a limiting spring 7q, a cutting knife 7r and sponge 7t, wherein the lifting sliding frame 7a is symmetrically and uniformly arranged in the middle of the mounting frame 1, the lifting slide bar 7b is uniformly arranged in the lifting sliding frame 7a, the first punching seat 7c is arranged at the upper end of the lifting slide bar 7b in a sliding fit mode, the first punching seat 7c is connected with the lifting sliding frame 7a through the punching spring 7e, the second punching seat 7d is arranged at the lower end of the lifting slide bar 7b in a sliding fit mode, the guide wheel 7g is uniformly arranged on the mounting frame 1 below the two ends of the second punching seat 7d in a rotating fit mode, the side wall of the first punching seat 7c is uniformly provided with connecting ropes 7f, the other end of the connecting rope 7f is connected with the second punching seat 7d, the middle part of the connecting rope 7f is abutted against the side wall of the guide wheel 7g in a rotation fit mode, the mounting frame 1 positioned below the second punching seat 7d is provided with a lifting cylinder 7h, the output shaft of the lifting cylinder 7h is connected with the second punching seat 7d, the side walls of the first punching seat 7c and the second punching seat 7d are symmetrically provided with sponges 7t with the same structural shape, the second punching seat 7d positioned on the inner side of the sponge 7t is symmetrically provided with punching sliders 7k in a sliding fit mode, the second punching seat 7d is internally provided with a punching cylinder 7j, the output shaft of the punching cylinder 7j is connected with a punching slider 7k, the side wall of the punching slider 7k is uniformly provided with limiting blocks 7n, the first punching seat 7c is symmetrically provided with punching notches 7m matched with the punching sliders 7k, evenly seted up spacing spout 7p in the punching press notch 7m, evenly install through sliding fit's mode in the spacing spout 7p with two 7d punching press seats on the stopper 7n that structural shape is the same, and the stopper 7n that is located spacing spout 7p is connected with punching press seat 7c through spacing spring 7q, evenly is provided with along its circumference on the punching press seat two 7d and cuts sword 7r, is provided with the notch of stepping down that cuts sword 7r of stepping down on the punching press seat 7 c.
During the specific work, firstly, an aluminum foil coil to be used for manufacturing a lunch box is sleeved on the conveying rotating shaft 4 manually, one end of the aluminum foil is pulled out and sleeved on the rolling rotating shaft 6, then, the rolling motor 8g is started to rotate, the driving rotating shaft 8c is further driven to rotate, the rolling rotating shaft 6 is further driven to rotate through the connection transmission of the synchronizing wheel 8h and the synchronizing belt 8j, the aluminum foil is further driven to be conveyed and rolled, in the process of rolling the aluminum foil, the arranged flattening rotating shaft 5 can flatten and compact the aluminum foil before punching operation through the bidirectional abutting effect, and the incomplete deformation of the lunch box in the punching process caused by the deformation of partial folds on the aluminum foil is avoided;
then, the second punching seat 7d is pushed to move to one side of the aluminum foil along the lifting slide bar 7b through the lifting air cylinder 7h, the connecting rope 7f is further driven to move, the first punching seat 7c is further pulled to synchronously move to one side of the aluminum foil along the lifting slide bar 7b after the connecting rope 7f is subjected to the steering action of the guide wheel 7g, the arranged punching spring 7e can enable the connecting rope 7f to be always in a tight state through the self elasticity, the preliminary positioning operation before the aluminum foil lunch box is punched is realized through the bidirectional synchronous movement of the first punching seat 7c and the second punching seat 7d, the sponge 7t arranged on the first punching seat 7c and the second punching seat 7d can elastically abut and clamp the outer edge of the lunch box during punching, the secondary flattening and compacting operation of the aluminum foil is carried out, after the first punching seat 7c and the second punching seat 7d are attached to each other, the circumferential cutting operation of the aluminum foil can be realized through the clamping fit between the cutting knife 7r and the abdication notch;
then, the stamping cylinder 7j pushes the stamping slider 7k to move towards the inside of the stamping notch 7m, the preliminary shaping of the lunch box can be realized through the mutual matching between the stamping slider 7k and the stamping notch 7m, the limiting block 7n on the stamping slider 7k is further driven to move while the stamping slider 7k moves, the limiting block 7n slidably mounted in the stamping notch 7m can perform abdicating contraction on the limiting block 7n on the stamping slider 7k, and the limiting block 7n on the stamping slider 7k synchronously enters the limiting sliding groove 7p, the bottom of the lunch box can generate bending deformation arranged at intervals through the clamping matching between the limiting block 7n and the limiting sliding groove 7p, the structural toughness in the later use process and the bearing capacity of the lunch box when food is filled can be further improved through the bending deformation of the lunch box, after the stamping of the lunch box is finished, move through two 7d of lift cylinder 7h pulling punching press seat, further make punching press seat 7c move that resets in step through the connection transmission of connecting rope 7f, after punching press slider 7k shifts out punching press notch 7m, the spacing spring 7q that sets up promotes the stopper 7n that is located spacing spout 7p inboard through self elasticity and moves that resets, further push the cutlery box that is located punching press notch 7m inboard through leaning on the effect and drop, later collect through artifical or current machinery after to the cutlery box that falls and deposit, and reset through punching press cylinder 7j pulling punching press slider 7k, so reciprocal, carry out the continuous stamping forming operation of cutlery box.
The winding mechanism 8 comprises a positioning frame 8a, a limiting slide ring 8b, a driving rotating shaft 8c, a compaction gear 8d, a driving gear 8e, a driving chain 8f, a winding motor 8g, a synchronous wheel 8h, a synchronous belt 8j, a compaction bottom plate 8k, a compaction chute 8m, a compaction spring 8n, a compaction rotating shaft 8p and a compaction unit 8q, wherein the positioning frame 8a is symmetrically and uniformly arranged on the mounting frame 1 between the winding rotating shaft 6 and the lifting carriage 7a from left to right, the limiting slide ring 8b is symmetrically and uniformly arranged on the side wall of the positioning frame 8a close to the middle part of the mounting frame 1 from top to bottom, the driving rotating shaft 8c is symmetrically and uniformly arranged on the positioning frame 8a at the inner side of the positioning slide ring from top to bottom through a bearing, one end of the driving rotating shaft 8c is uniformly provided with the driving gear 8e through a spline, the driving gear 8e is connected with the driving chain 8f, the compaction gears 8d which are symmetrically arranged up and down are mutually meshed for transmission, synchronizing wheels 8h are symmetrically arranged on the driving rotating shaft 8c and the winding rotating shaft 6 through splines, the synchronizing wheels 8h are connected for transmission through a synchronizing belt 8j, a winding motor 8g is arranged on the positioning frame 8a through a motor base, an output shaft of the winding motor 8g is connected with the driving rotating shaft 8c through a coupler, compaction bottom plates 8k are symmetrically arranged on the mounting frame 1 between the positioning frame 8a and the winding rotating shaft 6 in a left-right mode, compaction sliding grooves 8m are symmetrically arranged on the compaction bottom plates 8k up and down, compaction rotating shafts 8p are symmetrically arranged in the compaction sliding grooves 8m in a sliding fit mode, the compaction rotating shafts 8p are connected with the compaction bottom plates 8k through compaction springs 8n, and compaction units 8q are arranged on the limiting sliding rings 8 b.
The compacting unit 8q include compacting swivel 8q1, compaction shell fragment 8q2, compaction balladeur train 8q3, positioning spring 8q4 and location pivot 8q5, evenly overlap the cover through the spline on the drive pivot 8c and be equipped with compaction swivel 8q1, evenly be provided with compaction shell fragment 8q2 along its circumference on the lateral wall of compaction swivel 8q1, evenly install compaction balladeur train 8q3 through sliding fit on the spacing sliding ring 8b, compaction balladeur train 8q3 is connected with spacing sliding ring 8b through positioning spring 8q4 and evenly installs location pivot 8q5 on the compaction balladeur train 8q3 through the mode of running fit.
When the aluminum foil secondary compaction device works specifically, the rolling rotating shaft 6 is driven to rotate by the driving rotating shaft 8c, meanwhile, the driving rotating shafts 8c positioned at the upper side and the lower side of the aluminum foil are driven to synchronously rotate in opposite directions by the meshing transmission between the compaction gears 8d, the driving rotating shafts 8c which are uniformly arranged are further driven to synchronously rotate by the connecting transmission between the driving gear 8e and the driving chain 8f, the compaction elastic sheets 8q2 are further driven to synchronously rotate by the compaction rotating ring 8q1, the fold deformation areas on the rest aluminum foil strips can be flattened and compacted by the elastic abutting action of the compaction elastic sheets 8q2 which are symmetrically arranged at the upper side and the lower side of the aluminum foil, the positioning rotating shafts 8q5 can always abut against the aluminum foil under the pushing action of the positioning springs 8q4 by the vertically symmetrically arranged compaction carriages 8q3, and the secondary compaction operation of the aluminum foil after flattening can be carried out by the bidirectional rigid abutting action of the positioning rotating, promote the aluminium foil planarization of the remaining materials behind stamping forming, the compaction pivot 8p that sets up can lean on the aluminium foil after pacifying to lean on tightly under the promotion of compaction spring 8n, avoids rolling pivot 6 constantly to increase thickness change when carrying out the rolling operation to cause the slope fold of aluminium foil, reduces remaining aluminium foil and takes place cracked probability in the rolling process.
The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are given by way of illustration of the principles of the present invention, and that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.